Pneumatic polishing wheel



Patented Sept 21, 1938 TU-NITED s ATE PATENT OFFICE I mantismomsncrousnnvc war-m1. Clotaire Mary, Paris, France Application May :0,1037, Serial No.- ua'ioa In France May 20, me

1 Claim. (cl. 51-192) by means of bolts b and of inner circles b to side7 The invention has for its object improvements in pneumatic polishingwheels.

As is known, there already exist polishing wheels comprising a pneumaticdrum surroundedat its peripheryfby an abrasive annular band, theinflation of the inner drum determining the mannerof working on the workpiece. But said drums generally have two lateral metal annular partswhich retain the medial rubber. portion which is itself of relativelysmall thickness, so

, thatduri'ng operation there is a deformation of the medial peripheralband and the apparatus can only be used in practice for working partsvof rounded or convex shape and cannot serve for working on plainsurfacesand, a fortiori on concave-surfaces.

The improvements which'are the object of the invention aim at enablingpneumatic wheels 'of this kind to be used for all polishing work onflat, or even concave surfaces. For this purpose,

the resilient or rubber part of the drum forms both the medial part. andthe two annular side a ing and if desired the deformation of theabrasive band, which in this case of the drum. e

In its construction, the rubber part forming the resilient drumadvantageously comprises .a central thick portion preferably made ofpure gum and two more rigid lateral rubber portions. for example made ofrubber coated fabric, so as to ensure the correct maintenance of theannular shape of the drum, while permitting a cerhas the whole widthtain expansion and a relative flexibility of the medial portion.

The accompanying drawing illustrates, by way of example, one embodiment.of the improved pneumatic polishing wheel device which is the object ofthe invention. The single figure of said drawing is the vertical sectionof said wheel.

As seen in said drawing, the device comprises an annular rubber part a,of which the central portion a is relatively thick and made of pure gumfor example, whereas the-two side portions a? are 'of more rigidrubberand are formed for example by e. plurality of thicknesses of rubbercoated fabric. Said part a is fixed on either side cheeks c, which arefixed on the other hand to tion of plastic joints 1, and which are ofsuch diameter thattheir edge only extends 'to some distance from theouter peripheral surface of theresilient part a so that it can neverbeat on the work piece. A valve such as g-mounted in one of the cheeksc,-permits of the inflation of the annularspace between the hub d, thecheek c and the resilient part a. An inner tube can be. provided insidethe the hub c by means of bolts e with the interposi-a drum to ensure abetter sealing. The pneumatic chamber can be made in one piece, theresilient part a. being in form of closed torus.

II- V Around the resilient part a. is placedthe annular abrasive band Itconsisting of paper orof fabric carrying'on theoutsidetheabrasive mate-'rial. Said abrasive band is mounted on the drum before its inflation,and when the inflation has beeneffected it is held in position by saidinflation.

When the inflation of the drumis slight and consequently the abrasiveband remains flat, the

wheel can operate perfectly flat;,it can even come somewhat flattened onthe operative portion and expand over the latter. Owingto the settingback of the cheek c relatively to the outer surface of the resilientpart a and of the abrasive band, said cheeks canineverbear on-the workpiece, thereby enabling the drum to be used overthe whole of its.wi'dth.

' The inner pressure or air of the drum. com-. blned with the mechanicalapplication pressure,

of the wheel on the work piece, will be suitably determined according tothe work to be eiiected and the nature of the material to be polished.The wheehthus constructed can be used, either on machines having flxedframes, or on portable hand machines, or on rolling machines forpolishing flat surfaces of all kinds, made of metal, of wood, of marble,.of natural or artificial stones, etc., or for polishing concave-surfaces,-or mount ed at the end of a flexible transmission, or on apolishing head, etc.

Abrasive annular bands having slightly differ-- ent diameters canadvantageously be used with said wheel. with a reduced inflation thesmallest diameterof band will be used and said band as well as the wheelcan expand over the-surface greater diameter, it will be possible,'byconsiderably inflating the drum, to cause a certain bulging of its outersurface and to thus operate with the middle of said surface.

The changing of the abrasive. is very easily elected by deflation, thenby inflation or with the part to be polished, thereby enabling the wheelto be applied in theportable form, on a metal sheet or part withoutfearof deterioration.

2. Possibility, with a single wheel, of using polishing bands made ofabrasive fabric oi all kinds of grain, from the coarsest for trimming,to the flnest for polishing, and of changing said band in a few moments,.and the possibility likewise oi! using polishing bands made of bullleather which the user himself can cover or not, with abrasive material.

3. Possibility of using the wheel with slight inflation so as to polishall more or less deformed parts, oi a metal sheet, of a floor, of amould board of a plough, etc.', or with a greater inflation so as tobulge the operative surface and thus work on the middle of the latter.

It is obvious that the invention is not limited to the constructionaldetails which have been described and illustrated above and that it iscapable of any modifications.

What I claim and desire to secure by Letters Patent 0! the United Statesis: l

A pneumatic polishing wheel, comprising an annular drum having acomparatively thick and elastic central portion consisting of gum andextending over the entire width of the wheel, and

side portions situated at both sides of said central portion, said sideportions consisting of rubber coated fabrics and being less thick andless elastic than said central portion, an annular abrasive bandcovering said central portion, two metallic side cheeks situated at adistance one from the other and having annular outer end portions andinner end portions, the diameters of said outer end portions beingsubstantially smaller than the diameter of said central portion,

- means connecting the side portions of said drum with the outer endportions of said side cheeks, a

rotary shaft connected],with the inner end portions of said side cheeks,and means carried by one of the side cheeks for supplying air underpressure into the space between said side cheeks and said drum.

1 CLOTAIRE MARY.

